The Network Simulator - ns-2

Note: The project has migrated these web pages to a wiki. This page can now be found here.

Ns is a discrete event simulator targeted at networking research.
Ns provides substantial support
for simulation of TCP, routing, and multicast protocols
over wired and wireless (local and satellite) networks.

Ns began as a variant of the
REAL network simulator
in 1989 and has evolved
substantially over the past few years.
In 1995 ns development was supported by DARPA through
the VINT project
at LBL, Xerox PARC, UCB, and USC/ISI.
Currently ns development is support through DARPA
with SAMAN
and through NSF with CONSER,
both in collaboration with other researchers including ACIRI.
Ns has always included substantal contributions from other researchers,
including wireless code from
the UCB Daedelus and CMU Monarch projects and Sun Microsystems.
For documentation on recent changes,
see the version 2 change log.

Read this first:

While we have considerable confidence in ns,
ns is not a polished and finished product, but
the result of an on-going effort of research and development.
In particular, bugs in the software are still being
discovered and corrected. Users of ns are responsible for verifying
for themselves that their simulations are not invalidated by bugs.
We are working to help the user with this by significantly expanding
and automating the validation tests and
demos.

Similarly, users are responsible for verifying for themselves that
their simulations are not invalidated because the model implemented
in the simulator is not the model that they were expecting. The
ongoing Ns Manual should help in this process.